Li, Jiayu
Li, Jing
Jia, Ruixia
Wang, Yingquan
Qian, Sheng
Xu, Yong
Article History
Received: 6 November 2019
Accepted: 13 March 2020
First Online: 30 March 2020
Ethics approval and consent to participate
: This study was reviewed and approved by the ethics committee of the Health Development Research Center of Soochow University in Suzhou, Jiangsu, China. Participants were informed of the purposes and procedures before the study commenced. In accordance with Declaration of Helsinki, we obtained written informed consent from all students and one of their parents or legal guardians.
: Not applicable.
: The authors declare that they have no competing interests.